According to Medium, you owned your content. If you want to import stories from your blog to Medium then you have to add a rel==noncanocial tag so that if you tell the search engine that this post is published somewhere else and don't fetch it on Google search. Here how you can do that..
Don’t Do This Big Mistake While Importing Stories To Medium
Don’t do this mistake otherwise you will violate Medium Policies.
I hope this will helps you.